JP2008008955A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispose a support lens barrel on the outside of a rotatory cam cylinder although the support lens barrel is injection-molded from a resin. <P>SOLUTION: A rotatory cam cylinder 40 is formed by a cutting process. First to third cam holes 40a to 40c in which zoom rollers 52 are inserted, and a rotation restriction hole 40d are formed in the peripheral face of the rotatory cam cylinder 40 by a cutting process. A restriction roller 56 is inserted in the rotation restriction hole 40d. When the restriction roller 56 comes into contact with both the ends of the rotation restriction hole 40d, the rotation of the rotatory cam cylinder 40 is restricted. The support lens barrel 44 is formed by injection-molding the resin. A guide groove 44a and a mounting hole 44b are formed in the support lens barrel 44. After a restriction roller 56 is inserted into the rotation restriction hole 40d, the support shaft portion 57a of a roller support shaft 57 is inserted into a roller hole 56a. Then, the roller support shaft 57 is fixed to the support lens barrel 44 with a screw 58. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector that forms an image on a screen by forming image light with a projection lens.

  The projector is provided with a rotating cam cylinder for moving the lens in the optical axis direction. A ring-shaped or cylindrical lens frame is fixed to the lens (for example, see Patent Document 1). The lens frame is movably attached to the inside of a cylindrical rotating cam cylinder. An elongated cam hole is formed on the outer periphery of the rotating cam cylinder, and a lens roller inserted through the cam hole is attached to the outer periphery of the lens frame. A support barrel that rotatably supports the rotating cam cylinder is disposed inside the rotating cam cylinder. A flange portion protruding in the radial direction is formed at the rear end portion of the support barrel, and this flange portion is fixed to a fixing member inside the projector. The lens roller is inserted into the cam hole through the insertion hole formed in the support barrel. When the rotating cam cylinder is rotated, the lens frame moves in the optical axis direction, and projection of the lens roller is caused by the movement of the lens frame. Zoom the image.

  The cam hole is formed in the rotating cam cylinder by cutting because its dimensional control is severely required. On the other hand, the support barrel is formed by injection molding with resin in order to reduce costs.

  In recent years, in order to increase the zoom amount, there has been proposed a projector in which the movement amount of the lens frame is increased. In order to increase the amount of movement of the lens frame, it is necessary to increase the lengths of the rotating cam barrel and the support barrel.

However, since the support barrel is fixed to the fixing member at the flange portion at the rear end, there is a problem that when the length is increased, the stability when fixed is deteriorated. In view of this, it has been considered to dispose the support barrel outside the rotating cam barrel and to form the flange portion in front of the rear end portion of the support barrel. In this case, a long-hole-shaped rotation restricting hole for restricting the rotation of the rotating cam cylinder is formed in the support barrel, and a rotation restricting roller provided in the rotating cam cylinder is inserted into the rotation restricting hole to rotate the rotating cam cylinder. When the cam cylinder rotates, the rotation restricting roller comes into contact with the end of the rotation restricting hole so that the rotation of the rotating cam cylinder is restricted.
JP 2003-66316 A

  However, the support barrel is an injection-molded product made of resin, and the gate when the support barrel is injection-molded is provided on the rear surface, and at the time of injection molding, the resin flows from the rear surface toward the front surface side. For this reason, when the rotation restricting hole whose longitudinal direction is the vertical direction (the direction opposite to the resin flowing direction) is formed in the support barrel, the resin flow is deteriorated around the rotation restricting hole, and the molding stability is improved. There is a problem that the size of the rotation restricting hole cannot be controlled severely. When the size of the rotation restricting hole is abnormal, there is a problem that the rotation of the rotating cam cylinder is also abnormal and the movement of the lens frame in the optical axis direction is also abnormal.

  The present invention has been made to solve the above problems, and provides a projector capable of arranging a support barrel outside the rotating cam barrel while forming the support barrel by injection molding with resin. For the purpose.

  In order to solve the above-described problems, a projector according to the present invention includes: a projection lens that forms image light and projects an image on a screen; and a rotation lens that is rotatably provided and rotates the projection lens in the optical axis direction by rotation. And a support barrel that is provided outside the rotating cam barrel and rotatably supports the rotating cam barrel and is formed by resin injection molding; and formed on the rotating cam barrel. An engagement member that engages with the rotation restriction hole formed; a support shaft that is provided in the support barrel and supports the engagement member; and the rotation cam cylinder rotates, and the engagement member The rotation of the rotating cam cylinder is restricted when contacting the end of the rotation restricting hole. Examples of the resin constituting the support barrel include polycarbonate. The support shaft may be formed integrally with the support barrel, which is formed of a member different from the support barrel. Furthermore, it is preferable to form the rotation restricting hole in the rotating cam cylinder by cutting, and examples of the material constituting the rotating cam cylinder include aluminum and brass. The end of the rotation restricting hole with which the engaging member abuts indicates the wall surface of the rotating cam cylinder formed by the end of the rotation restricting hole.

  Moreover, it is preferable that the said engaging member is comprised from the roller rotatably supported by the said support shaft. Examples of the material constituting the roller include polyacetal and brass.

  Further, the support shaft preferably includes a roller support shaft that rotatably supports the roller; and a holding member that is inserted through an insertion hole formed in the support barrel and holds the roller support shaft. . Examples of the holding member include a screw and a resin member.

  Further, it is preferable that a cam hole for moving the projection lens in the optical axis direction is formed in the rotating cam cylinder by cutting.

  According to the projector of the present invention, a projection lens that forms image light and projects an image on a screen; a rotary cam cylinder that is rotatably provided and moves the projection lens in the optical axis direction by rotation; and a rotary cam cylinder A support barrel formed by resin injection molding; an engagement member that engages with a rotation restricting hole formed in the rotary cam cylinder; A support shaft that is provided on the lens barrel and supports the engaging member; and the rotation of the rotating cam cylinder is restricted when the rotating cam cylinder rotates and the engaging member contacts the end of the rotation restricting hole. Therefore, the support barrel can be arranged outside the rotating cam barrel while the support barrel is formed by resin injection molding. Further, a flange portion for fixing the support barrel inside the projector can be formed other than the rear end portion of the outer peripheral surface of the support barrel, and the rotation cam barrel and the support are provided to increase the amount of movement of the projection lens. Even when the length of the lens barrel is increased, the support lens barrel can be fixed inside the projector while maintaining stability.

  Further, since the engaging member is composed of a roller that is rotatably supported by the support shaft, the contact resistance between the engaging member and the rotating cam cylinder can be reduced.

  FIG. 1 shows an appearance of a projector 10 embodying the present invention. When the projector 10 is used, the first projection lens 11 is exposed on the front surface of the housing 14 by opening the lens cover. A second projection lens 12 and a third projection lens 13 are disposed behind the first projection lens 11 in the housing 14. A screen 15 (see FIG. 2) is disposed in front of the first projection lens 11, and an image is projected from the first projection lens 11. A rotary zoom dial 16 is provided on the upper surface of the housing 14, and the projection images (projected on the screen 15) by the first to third projection lenses 11 to 13 are operated by operating (turning) the zoom dial 16. Zoom). When the zoom dial 16 is rotated in directions A and B in FIG. 1, the zoom of the projected image is adjusted.

  FIG. 2 shows a schematic configuration diagram of the projector 10. Inside the housing 14, a light source 21, an illumination optical system 22, a total reflection prism 23, a DMD 24, a projection optical system 25, a zoom adjustment mechanism 26, and the like are provided. As the light source 21, for example, a white light source such as a xenon lamp or a mercury lamp is used. The illumination light emitted from the light source 21 enters the illumination optical system 22.

  The illumination optical system 22 includes a color wheel 31, a rod integrator 32, relay lenses 33 and 34, and a mirror 35. The color wheel 31 separates the illumination light from the light source 21 into B, G, and R colors in a time-sharing manner. The color wheel 31 has three color filters, a B filter that transmits only B light, a G filter that transmits only G light, and an R filter that transmits only R light, from the rotation center of the substrate. They are arranged at approximately the same distance. The color wheel 31 rotates at high speed and sequentially inserts the filters of each color into the illumination optical path. As a result, the illumination light is color-separated into three colors of B, G, and R in a time-sharing manner, and the separated light of each color is sequentially emitted toward the DMD 24.

  The rod integrator 32 is made of, for example, glass and has a reflection surface formed on the inner side. The light separated by the color wheel 31 is homogenized by repeating reflection while passing through the rod integrator 32. The relay lenses 33 and 34 relay the light beam emitted from the rod integrator 32 to the mirror 35. The mirror 35 reflects this light beam toward the total reflection prism 23.

  The total reflection prism 23 separates incident light incident on the DMD 24 from the mirror 35 and reflected light reflected by the DMD 24. The total reflection prism 23 is composed of, for example, two triangular prisms having different refractive indexes, and a reflection surface 24a is formed at the boundary between the two triangular prisms. Since the incident light has an incident angle larger than the critical angle, the incident light is totally reflected by the reflecting surface 24 a and enters the DMD 24. On the other hand, the reflected light reflected by the DMD 24 is transmitted through the reflecting surface 24a because the incident angle is smaller than the critical angle.

  As is well known, the DMD 24 has a large number of mirror elements corresponding to pixels arranged in a matrix on the light receiving surface. Each mirror element changes the reflection direction of the received illumination light by changing the angle based on the projected image. When displaying a pixel brightly, the mirror element is displaced to the on position, and the received light is reflected toward the projection optical system 25 as on light. On the other hand, when the pixel is displayed darkly, the mirror element is displaced to the off position, and the received light is reflected as off light in a direction away from the projection optical system 25. The image light is constituted by a set of on-lights directed toward the projection optical system 25.

  As shown in FIGS. 2, 3, and 4, the projection optical system 25 includes a rotating cam barrel 40, a first lens unit 41 having the first projection lens 11, and a second lens unit having the second projection lens 12. 42, a third lens unit 43 having a third projection lens 13, and a support barrel 44. The first to third lens units 41 to 43 are disposed in the rotating cam cylinder 40. As will be described in detail later, the first to third lens units 41 to 43 are provided so as to be movable in the C direction and the D direction in FIGS. 2 and 3. The image light generated by the DMD 24 is imaged on the screen 15 by the projection optical system 25. As a result, an image is projected on the screen 15. The number of projection lenses constituting the projection optical system 25 is not limited to three and can be changed as appropriate.

  The rotating cam cylinder 40 is made of aluminum die cast and is formed into a cylindrical shape by cutting. On the outer peripheral surface of the rotating cam cylinder 40, first to third cam holes 40a to 40c having long holes through which the zoom rollers 52 of the first to third lens units 41 to 43 are inserted are formed by cutting. ing. Three each of the first to third cam holes 40a to 40c is formed at a 120 ° pitch. In the first to third cam holes 40a to 40c, when the rotating cam cylinder 40 is rotated in the clockwise direction, the first lens unit 41 moves rearward (direction D in FIG. 3), and the second lens unit 42 moves rearward. When the third lens unit 43 moves forward (C direction in FIG. 3) and the rotating cam barrel 40 rotates counterclockwise, the first lens unit 41 moves forward and the second lens The unit 42 is formed to move forward and the third lens unit 43 to move backward.

  On the outer peripheral surface of the rotating cam cylinder 40, a rotation restricting hole 40d is formed by cutting. A restriction roller (engagement member) 56 for engaging with the rotation restriction hole 40d and restricting the rotation of the rotating cam cylinder 40 is inserted into the rotation restriction hole 40d. The rotation restricting hole 40d and the first to third cam holes 40a to 40c are configured so that each zoom roller 52 is in contact with the first to third cam holes 40a to 40 when the restricting roller 56 contacts both ends of the rotation restricting hole 40d. It is formed in a size that does not come into contact with both end portions. Thereby, the rotation of the rotating cam cylinder 40 is restricted by the restriction roller 56 coming into contact with both end portions of the rotation restricting hole 40d, specifically, the wall surface of the rotating cam cylinder 40 formed by both end portions of the rotation restricting hole 40d. The That is, when the restricting roller 56 comes into contact with both end portions of the rotation restricting hole 40d, the zoom amounts for enlargement and reduction are maximized.

  An attachment hole 40e for attaching an operation screw 45 described later is formed on the outer peripheral surface of the rotating cam cylinder 40. The mounting hole 40e is threaded so as to mesh with the threaded shaft portion 45a of the operation screw 45.

  An operation screw 45 is attached to the attachment hole 40e. The operation screw 45 includes a threaded shaft portion 45a and a head portion 45b, and the shaft portion 45a meshes with the mounting hole 40e while being covered with a resin operation cover 46. The operation cover 46 is operated when the zoom adjustment mechanism 26 rotates the rotary cam cylinder 40 to perform zoom adjustment of a projected image (image projected on the screen 15), and an operation screw 45 is inserted therein. Two stepped insertion holes 46a are formed. When the operation screw 45 is inserted into the insertion hole 46a, it is covered with the operation cover 46.

  The zoom adjustment mechanism 26 performs zoom adjustment of the projected image (image projected on the screen 15) by rotating the rotary cam cylinder 40 and moving the first to third projection lenses 11 to 13. The rotary cam cylinder 40 is rotated to move the first to third projection lenses 11 to 13 so that the projection image is zoomed according to the rotation angle (operation amount) of the dynamic zoom dial 16.

  As shown in FIG. 5, the first lens unit 41 includes a first projection lens 11 and a lens holder 50. The lens holder 50 includes a holder main body 51 that is fixed to the first projection lens 11, a polyacetal zoom roller 52 that engages with a first cam hole 40 a formed in the rotating cam cylinder 40, and a zoom roller 52 that is detachable. And a roller support portion 53 that is rotatably supported. Three roller support portions 53 are attached to the outer peripheral surface of the holder main body 51 at a 120 ° pitch, and each roller support portion 53 supports the zoom roller 52 in a rotatable manner. In addition, when the lens holder 50 is fixed to the first projection lens 11, the length from the center of the first projection lens 11 to the outer peripheral surface of the roller support portion 53 of the first projection lens 11 and the lens holder 50 is rotated. The cam cylinder 40 is formed to be slightly smaller than the inner peripheral radius. Thereby, the first lens unit 41 can be inserted into the rotary cam barrel 40 in a state where the zoom roller 52 is removed from the lens holder 50.

  The zoom roller 52 is formed so as to protrude from the outer peripheral surface of the rotary cam barrel 40 when the first lens unit 41 is assembled to the rotary cam barrel 40. The zoom roller 52 attached to the roller support 53 and protruding from the outer peripheral surface of the rotary cam barrel 40 is inserted into a guide groove 44a (see FIGS. 3 and 6) formed as a straight guide formed on the support barrel 44. . The guide groove 44a is formed linearly in the direction of the projection optical axis, so that when the rotary cam cylinder 40 is rotated, the first to third lens units 41 to 43 move in the direction of the projection optical axis. .

  Similar to the first lens unit 41, the second lens unit 42 includes the second projection lens 12 and the lens holder 50, and the third lens unit 43 includes the third projection lens 13 and the lens holder 50.

  As shown in FIG. 6, the support barrel 44 is formed in a cylindrical shape by injection molding of resin (for example, polycarbonate, etc.), and a guide groove 44 a as a straight advance guide of the zoom roller 52 and a regulation roller 56 are attached. Mounting holes (insertion holes) 44b are formed. The guide groove 44a is linearly formed in the projection optical axis direction. Three guide grooves 44a are formed at a 120 ° pitch. Note that the gate for injection molding the support barrel 44 is provided on the rear surface, and at the time of injection molding, resin flows from the rear surface toward the front surface side. Thus, molding defects do not occur due to the deterioration of the resin flow around the guide groove 44a whose longitudinal direction is the front-rear direction (the direction in which the resin flows) and around the circular mounting hole 44b.

  A flange portion 44 c is formed on the outer peripheral surface of the support barrel 44 in front of the rear end portion, and the flange portion 44 c is fixed to a fixing member inside the projector 10.

  An insertion hole 44 d for inserting the operation screw 45 and the operation cover 46 is formed on the outer peripheral surface of the support barrel 44. The insertion hole 44d has a size that prevents the operation cover 46 from coming into contact with the support barrel 44 when the rotating cam cylinder 40 to which the operation screw 45 and the operation cover 46 are attached is rotated within a rotatable range. Even when a dimensional error occurs during injection molding (for example, when molding is smaller than the standard dimension), the operation cover 46 is formed in a size that does not contact the support barrel 44.

  When the operating screw 45 is attached to the rotating cam barrel 40, after the rotating cam barrel 40 is engaged with the support barrel 44, the shaft portion 45a of the operating screw 45 is inserted into the insertion hole 46a and the insertion hole 44d of the operating cover 46. It is inserted and meshed with the mounting hole 40e. Thereby, the operation screw 45 is attached to the rotating cam cylinder 40 in a state covered with the operation cover 46. Then, the zoom adjustment mechanism 26 operates the operation cover 46 to rotate the rotating cam cylinder 40.

  A mode in which the first lens unit 41 is assembled to the rotary cam barrel 40 and the support barrel 44 will be described. The same applies to the manner in which the second lens unit 42 and the third lens unit 43 are assembled to the rotary cam barrel 40.

  First, after the zoom roller 52 is removed from the lens holder 50, the first lens unit 41 is inserted into the rotating cam cylinder 40, and then the rotating cam cylinder 40 is attached to the support mirror as shown in FIG. Insert into the tube 44. Then, the base side of the zoom roller 52 is inserted into the guide groove 44 a and the first cam hole 40 a of the support barrel 44 and attached to the roller support portion 53. Note that a cover cylinder (not shown) that covers the support barrel 44, the operation cover 46, the zoom roller 52, and the screw 58 is attached to the outside of the support barrel 44. 52 and the screw 58 cannot be touched.

  Next, as shown in FIG. 7B, after a polyacetal restriction roller 56 is inserted into the rotation restriction hole 40 d of the rotating cam cylinder 40, the support shaft portion of the roller support shaft 57 is inserted into the roller hole 56 a of the restriction roller 56. 57a is inserted. Then, a screw (holding member) 58 is inserted into the attachment hole 44 b and screwed into the support shaft hole 57 b of the roller support shaft 57 to fix the roller support shaft 57 to the support barrel 44. A roller receiving portion 57c is formed on the roller support shaft 57, and the restriction roller 56 is positioned in the rotation restriction hole 40d. The outer diameter of the regulating roller 56 is formed so as to be substantially the same as the width of the rotation regulating hole 40d in the left-right direction in FIG. 7 so that no gap is formed. It is formed so as not to have a gap substantially coincident with the outer diameter of 57a, and the thickness (length in the vertical direction in FIG. 7) of the regulating roller 56 is from the inner surface of the support barrel 44 to the roller receiving portion 57c. It is formed so as not to generate a gap substantially coincident with the distance to the upper surface of the roller, so that the regulating roller 56 is supported without rattling.

  The operation of the projector 10 configured as described above will be described. When the user rotates (operates) the rotary zoom dial 16, the zoom adjustment mechanism 26 rotates the rotating cam cylinder 40 and moves the first to third projection lenses 11 to 13, thereby projecting images. Zoom adjustment of the image projected on the screen 15 is performed. When the rotating cam cylinder 40 is rotated for this zoom adjustment, the restricting roller 56 comes into contact with both ends of the rotation restricting hole 40d, whereby the rotation of the rotating cam cylinder 40 is restricted. When the restricting roller 56 comes into contact with both end portions of the rotation restricting hole 40d, each zoom roller 52 does not come into contact with both end portions of the first to third cam holes 40a-40.

  In this way, the rotation restricting hole 40d is formed in the rotating cam cylinder 40 by cutting, the mounting hole 44b is formed in the support barrel 44 formed by resin injection molding, and the roller support shaft 57 and the screw 58 are used. Since the regulating roller 56 is rotatably disposed in the rotation regulating hole 40d, the supporting barrel 44 can be disposed outside the rotating cam barrel 40 while the supporting barrel 44 is formed by injection molding with resin. .

  Further, a flange portion 44c for fixing the support barrel 44 inside the projector 10 can be formed in front of the rear end portion of the support barrel 44, and the first to third projection lenses 11 to 13 are moved. Even when the lengths of the rotating cam barrel 40 and the support barrel 44 are increased in order to increase the amount, the support barrel 44 can be fixed inside the projector 10 while maintaining stability.

  In the above-described embodiment, the roller support shaft 57 is fixed to the support barrel 44 by the screw 58. However, the present invention is not limited to this, and the roller support shaft 57 can be fixed in a state where the restriction roller 56 is supported. For example, the roller support shaft 57 may be fixed to the support barrel 44 by a resin product having a claw portion formed at the tip.

  In the above embodiment, the regulation roller 56 is supported so as not to be rattled. However, if there is no rattling, the regulation roller 56 may be supported rotatably, and can be changed as appropriate. .

  In the above embodiment, the restriction roller 56 is arranged in the rotation restriction hole 40d using the roller support shaft 57 and the screw 58. However, the restriction roller 56 is not limited to this, and the restriction roller 56 is placed in the rotation restriction hole 40d. For example, the restriction roller 56 may be supported by a single member, and further, the restriction roller 56 can be rotated by a support portion formed integrally with the support barrel 44. You may make it support.

It is an external view which shows a projector. It is explanatory drawing which shows the schematic structure of a projector. It is a perspective view which shows a projection optical system. It is a perspective view which shows a rotation cam cylinder. It is a perspective view which shows a 1st lens unit. It is a perspective view which shows a support barrel. It is side surface sectional drawing which shows the 1st-3rd lens unit, a rotation cam cylinder, a support barrel, a control roller, a roller spindle, and a screw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Projector 11-13 1st-3rd projection lens 25 Projection optical system 40 Rotating cam cylinder 40a-40c 1st-3rd cam hole 40d Rotation restriction hole 41-43 1st-3rd lens unit 44 Support lens barrel 44a Guide Groove 44b Mounting hole (insertion hole)
56 Restriction roller (engagement member)
57 Roller spindle 58 Screw (holding member)

Claims (4)

A projection lens that forms image light and projects the image onto a screen;
In a projector provided with a rotating cam cylinder provided rotatably and moving the projection lens in the optical axis direction by rotation,
A support lens barrel that is provided outside the rotating cam barrel and rotatably supports the rotating cam barrel, and is formed by resin injection molding;
An engaging member that engages with a rotation restricting hole formed in the rotating cam cylinder;
A support shaft provided on the support barrel and supporting the engagement member;
The projector according to claim 1, wherein the rotation of the rotating cam cylinder is restricted when the rotating cam cylinder rotates and the engagement member comes into contact with an end of the rotation restricting hole.   The projector according to claim 1, wherein the engagement member includes a roller rotatably supported by the support shaft.   The support shaft includes a roller support shaft that rotatably supports the roller, and a holding member that is inserted through an insertion hole formed in the support barrel and holds the roller support shaft. The projector according to claim 2.   4. The projector according to claim 1, wherein a cam hole for moving the projection lens in the optical axis direction is formed in the rotating cam cylinder by cutting.

Images